Background: Cancer can lead to fatigue and the manifestation of psychological symptoms in patients, including depression, anxiety, and stress.

Objectives: The aim of this study was to investigate the relationship between fatigue and psychological symptoms in patients with gastrointestinal cancer.

Materials and Methods: The study had a descriptive, cross-sectional design. We assessed levels of fatigue and the psychological health of 70 patients with gastrointestinal cancer who had been referred to the cancer institute in Tehran, Iran in 2014.We used the Rhoten Fatigue Scale to assess patients’ levels of fatigue and the Depression Anxiety Stress Scale (DASS-21) to assess their psychological symptoms. We performed a correlation analysis and stepwise multiple linear regression to compare the relationship between fatigue and psychological symptoms in the cancer patients.

Results: There was a significant relationship between psychological symptoms, including depression, stress, and anxiety and fatigue in patients with gastrointestinal cancer (p<0.05).

Conclusion: Our study results demonstrate that the severity of fatigue is related to the extent of psychological symptoms (depression, anxiety, and stress) in patients with cancer. A patient’s depression and anxiety predicts the fatigue.